prt86a wrote:If its just based on LSN data, why does each school seem to have a different index scale? Do we know if Columbia actually uses a scale similar to the LSP 4.x one?

Each school publishes their own index. If you look at the index column on LSP you'll see they're all different, with some being low as 3.x and others higher than 200. the 4.x one is Columbia's official index.

Also I don't know if someone posted the actual index formula, but I didn't see it so if y'all are curious: